Hand-operated machines for cutting mat board used in picture framing are well known in the art. Generally, such machines include a base, to which may be mounted a clamping bar for holding the mat board in position thereupon during the cutting operation. In some forms, the clamping bar will have a shaft or rail supported upon it, which in turn serves to guide a cutting head or trolley across the workpiece. Since, in the usual case, the sight opening for the framed picture will be defined by beveled edges, the cutting heads have often been provided with holders for two blades, one holder being disposed to position a blade to cut perpendicularly with respect to the supporting surface, the other being disposed to position a second blade at an acute angle (typically, about 55 degrees) thereto.
The patent art with respect to machines and devices for cutting mat board and similar workpieces is quite voluminous. A fair representation thereof is believed to be constituted by the following United States Patents: Smith U.S. Pat. No. 228,686; Gaylord No. 491,307; Wheeler No. 513,851; McCall No. 570,180; Drinkaus No. 611,238; Gaffney No. 1,235,459; Williams No. 1,250,538; Buckingham No. 1,529,340; Simpson No. 1,897,534; Matthews 2,013,893; Smith 2,065,761; Tourneau No. 2,342,946; Carpenter No. 2,413,544; Schlitters No. 2,449,327; Pulsifer No. 2,581,602; Zelewsky No. 3,095,247; Eno No. 3,130,622; Shapiro No. 3,463,041; Ellerin No. 3,527,131; Hearns No. 3,543,627; Rogers No. 3,628,412; Decker No. 3,702,716; Rosetti No. 3,712,166; McBride No. 3,768,357; Martin No. 3,897,706; Kupersmith No. 3,903,767; Chaffin No. 3,953,086; Schwartz No. 3,964,360; Stowe No. 3,973,459; Logan No. 3,996,827; Jones No. 4,022,095; Meshulam No. 4,064,626; Ward No. 4,096,631; Larson No. 4,202,233; Rempel No. 4,413,542; Gelfand No. 4,440,055; Davis No. 4,503,612; Heathe No. 4,518,205; Bruns No. 4,570,516; and Sobel No. 4,590,834.
The patents to Simpson, Lanblad et al and Bruno are of some specific interest to the instant invention. Simpson provides apparatus having a cutter carriage, on which is mounted a presser wheel carried by an adjustable guide bar. The device of the Linblad et al patent employs a cutting assembly having guide wheels adjustably mounted on its opposite sides, which ride upon a track provided by parallel rail members. Bruno discloses a cutter-carrying body having a plurality of slippery polymeric wear buttons which project from its bottom surface, at least one of the buttons being adjustable to vary the extent of its projection.
Despite the activity indicated by the foregoing, the need remains for a head assembly for a mat cutting machine which is capable of smooth and reliable operation, to produce accurate and precisely located cuts on the workpiece, and it is therefore the broad object of the present invention to provide a novel head assembly having those capabilities, as well a novel mat cutting machine in which it is incorporated.
It is a related object of the invention to provide such a cutting head in which the position of the blade for bevel cutting can readily be adjusted, without removal from the machine, and while also being securely maintained once established.
Another related object is to provide such a novel machine, in which the adjustment of the bevel-cutting blade is readily made with respect to the clamping bar.